Earthworms have no skeleton,but during burrowing the anterior end becomes turgid and acts as a hydraulic skeleton. It is due to

The $DNA$ of $E. coli$ is . . . . . . .

Initially a photon of wavelength $\lambda_1$ falls on a photocathode and emits an electron of maximum energy $E_1$. If the wavelength of the incident photon is changed to $\lambda_2$,the maximum energy of the electron emitted becomes $E_2$. Then the value of $hc$ ($h=$ Planck's constant,$c=$ velocity of light) is

Which compound is soluble in $NH_4OH$?

Where is the compound squamous epithelium found?

If $y=y(x)$ is the solution of the differential equation $x\frac{dy}{dx} + 2y = x^2$ satisfying $y(1)=1$,then $y\left(\frac{1}{2}\right)$ is equal to